Method of repairing furnace walls



Sept. 23, 1952 K 2,611,330

METHOD OF REPAIRING FURNACE WALLS Filed June 19, 1947 2 SHEETS--SHEE'I l /9 /9 j) j W U 5 I I /4 /6 /j M f: 7 L 20 Ii /7 /7 g I /7 I 4 /4 I r [j 7C4 Eta IN VEN TOR.

HA9 1977 0171115 Y Sept. 23', 1952 L. M. KIRK 2,611,330

METHOD OF REPAIRING FURNACE WALLS Filed June 19, 1947 2 'SHEETSSHEET 2 INVENTOR.

L owl/ M. fUf/f Patented Sept. 23, 1952 1 UNITED STATES PATENT OFFICE 2,611,330 7 1 METHOD OF REPAIRING FURNACE WALLS 7 Lowell M. .Kirk, Gary, Ind., assignor to "United States Steel Company, a

Jersey corporation or New 3 Claims. (Chime-'1) l This invention relates to methods for repairing furnace walls and to preformed replacement units and apparatus for installing the same.

The present invention is particularly appli cable for repairing open hearth furnaces, wherein door jambs and arches often become damaged prematurely during furnace operation and must be replaced. These parts commonly are of refractory brickwork, and the usual practice in replacing them has been to clean out the damaged. parts and re-lay the new bricks manually. This practice has disadvantages in that furnaces must be cooled to temperatures sufliciently low for workmen to lay bricks, resulting in considerable loss of furnace time, and even though furnaces are cooled, work is performed at temperatures uncomfortably not to workmen. Further, the bricks are subject to thermal shock, as they are cold when placed, and spalling may occur.

Although the present invention is described in connection with the repair of open hearth furnaces, it is apparent that the principles described may be applied to the repair of other types of furnaces, for example, heating furnaces.

An object of the present invention is to provide improved methods for replacing damaged door jambs'cr arches, by employment of which the foregoing disadvantages are eliminated, and replacementof these parts is greatly facilitated.

A further object of the invention is to provide methods for replacing door jambs and "arches wherein these parts are constructed as preformed units and are installedln furnace walls mechanically by handling apparatus operated by conventional charging machines or "other motive means.

Further objects'of the invention are to provide preformed assembled units suitable for placement in furnace walls to form door lambs and other units cooperable therewith to form arches; to construct such units of refractory brickwork bound together with straps and adapted to'be preheated to furnace temperature and installed in furnace walls by mechanical means; and to provide handling apparatus operable by furnace charging machines for placing such units in furnace'walls.

In accomplishing these and other objects of the present invention, I have provided improved units and apparatus and m'ethodsof repairing furnaces therewith, preferred forms of units'and apparatus being shown in the accompanying drawings, wherein:

Figure 1 is a perspective view from the interior of an open hearth furnace, the wall of which has installed therein a pair of lamb .units and an arch unit constructed in accordance with "the present invention; V Figure .2 is a side elevational view, partly .in section, of a form such as may be employed, in assembling arch units;

Figure 3 is a top plan view illustrating the installation of a jamb unit in the furnace wall;

Figure 4 is a top plan view illustrating the removal of the jamb unit in the furnace wall;

Figure 4 is a top plan View illustrating the removal of the jamb handling apparatus after placement of the jamb unit; 1 Y i Figure 5 is a sectional view illustrating one means-by which the handling apparatus may en gage the jamb unit, the view being takenlsubstantially on line VV of Figure 3; and

Figure 6 is a perspective view illustrating the installation of an arch unit.

Referring more in detail to the drawings:

In Figure 1 there is shown a pair of jamb units Ill and a cooperating mating arch unit H installed in an open hearth furnace wall. The jamb units are supported on seats 12 and are positioned behind buckstays 3. The structure of the furnace is otherwise conventional and hence is not shown in detail.

In accordance with the present invention, jamb units iii are constructed of refractory bricks M of any material suitable for use in furnace linings of the type involved. The bricks are laidremote from the furnace to form a unit of desired size and shape, preferably without mortar, and are bound together by straps [5, preferably of steel. The upper end edges of the units have skews 16 for support of arches H, hereinafter described. Notches ll are formed in opposite end faces of unit ill and are adapted to be engaged by the handling apparatus in placing or installing the unit in a manner hereinafter described.

Arch unit ll, cooperable with jamb units lllfis constructed of bricks i8, likewise of any material suitable for use in the particular type of furnace, and bound together by straps l9. edges of said arch units have skews 20 adapted to mate with skews It of the iamb units for supporting the arch across a pair of jamb units.

Preferably a form, such as that illustrated in Figure 2, is employed in assembling bricks for the arch unit. The form comprises vertical supports 2! and 22 on which are fixedly mounted angle iron side rails 23 and 24. The upstanding legs of side rails 23 and-2-4 are inclined from the vertical by angles equal to the angles of skews 20 on the arch unit. A centerpiece 25, having an arcuate bot tom member 26., isadapted to rest on said side The lower end rails and may be lifted off, as when an arch unit has been constructed thereon. Underneath bottom member 26, the centerpiece has an inverted box 21 for engagement with handling apparatus hereinafter described.

The arch unit is constructed by assembling the bricks, preferably without mortar, on centerpiece 25 and strapping them together.

The handling apparatus for installing the jamb units in a furnace wall is illustrated in Figures 3, 4 and 5. Said apparatus includes a yoke 28 bent to form a shorter arm 29 and a longer arm 30 in spaced parallel relation. Arm 29 carries means for detachably securing the yoke to a-ram .3! of a charging machine, not shown, but which may be of any suitable construction as known in the art.

Arm 30 carries inwardly projecting fingers 32 and 33 spaced apart a suitable distance to fit within notches I! in opposite end faces of jamb unit I and of slightly narrower height than said notches. In one form of the invention th upper and lower faces of the fingers are smooth and the handling apparatus may be inverted to engage J'amb units from either side. In the form shown in Figure 5, said fingers terminate in hook portions 34 that engage the side faces of the unit to-effect a positive engagement unless the yoke is lowered. In the lowered position of the yoke said books can be slid freely through the notches for removal of the apparatus.

The handling apparatus for installing cooperating arch units is illustrated in Figure 6. Said apparatus includes a head 35 adapted to be removably secured to ram 3|. The upper face of head 35 is adapted to fit within inverted box 21 of the centerpiece 25 and thereby to carry the arch unit which the latter is resting on said centerpiece.

In effecting furnace repairs using the methods of the present invention, cooperable jamb and arch units constructed as described preferably, though not necessarily, are preheated to approximately the temperature at which the furnace is to be repaired in order that the units may be placed in the furnace at this temperature. Thus thermal shock, such as causes spalling, is largely eliminated. It is understood by those skilled in the art of furnace repair that a furnace is not fired while undergoing major repairs of this nature. Consequently the furnace cools and is repaired at an elevated temperature somewhat below its operating temperature.

The brickwork in the jambs and arches-to be replaced is cleaned out manually or by suitable mechanical means and seats l2 are prepared. The seats may conveniently be prepared by cutting back the brickwork and spreading chrome mortar thereover.

A jamb unit in is then engaged by fingers 32 of the jamb handling apparatus fitting within notches I1 and carried within the furnace behind buckstays IS in a path as indicated by the arrows in Figure 3, the operation preferably being performed by the charging machine. Yoke 28 is then lowered slightly so that the upper edges of the fingers clear the edges of notches l1 and the movement of the apparatus is reversed and the apparatus withdrawn from the furnace, as indicated by the arrows in Figure 4.

If desired, yokes having hooked fingers 34 (Figure may be designed as rights and lefts so that arch units on either side of a furnace door may be inserted through the same door. Therefore the showing of Figures 3, 4 and 5 is not to be construed as limiting the invention to use in connection with left hand door jambs.

After placement of a pair of jamb units by the steps described, an arch unit I! is placed thereacross. Said arch unit is initially supported on centerpiece 25, which in turn is engaged by head 35 carried by ram 31. When the arch unit is in place and supported by skews 20 resting on skews [6, the ram is lowered and withdrawn and with it head 35 and centerpiece 25 are also withdrawn.

After placement of the jamb and arch units, bricks are laid manually to fill any voids, such as notches l1 and the open spaces above the area of contact of skews I6 and 20 and the clearance spaces above the units.

As the furnace is subsequently heated, straps l5 and [9, having served their purpose, are burned away, and th bricks are fused together to form permanent door jambs and arches.

.From the foregoing description, it is seen that I have provided improved methods of effecting jamb and arch replacement that not only expedite the work, but also make the Work less arduous and more permanent, since spalling is largely prevented.

While I have shown but certain designs of units and apparatus, and described but certain exemplary methods, it is apparent that modifications may arise. Therefore I do not wish to be limited by the disclosure set forth, but only by the scope of the appended claims.

I claim:

1. In the art of repairing a furnace, a method of replacing a vertical side wall section thereof which contains an opening and with the furnace at an elevated temperature that normally causes spalling of cold bricks when said bricks are placed in contact with said heated furnace structure comprising preforming two jamb units and an arch unit of refractory brick, binding the bricks of each of said units together with steel straps, preheating said units to approximately said elevated temperature, mechanically placing one of said jamb units in the wall, mechanically placing the other jamb unit in the wall spaced from said first jamb unit, mechanically placing said arch unit in the wall across said jamb units, said jamb and arch units being at this elevated. temperature when placed in the wall thereby avoiding thermal shock, and heating the furnace: to a higher temperature sufficient to burn away said straps and fuse the brickwork of said jamb. and arch units.

2. In the art of repairing a furnace, a method of replacing a jamb in a vertical side wall thereof which contains an opening and with the furnace at an elevated temperature that normallycauses spalling of cold bricks when said bricks are placed in contact with said heated furnace structure comprising preforming a jamb unit of refractory brick, binding the bricks of said jamb unit together with steel straps, preheating said jamb unit to approximately said elevated temperature, mechanically placing said jamb unit in the wall, said jamb unit being at this elevated temperature when placed in the wall thereby avoiding thermal shock, and heating the furnace to a higher temperature suflicient to burn away said straps and fuse the brickwork of said jamb unit.

3. In the art of repairing a furnace, a method of replacing an arch in a vertical side wall thereof which contains an opening and with the furnace at an elevated temperature that normally 5 causes spalling of cold bricks when said bricks are placed in contact with said heated furnace structure comprising preforming an arch unit of refractory brick, binding the bricks of said arch unit together with steel straps, preheating said arch unit to approximately said elevated temperature, mechanically placing said arch unit in the wall across a pair of jambs, said arch unit being at this elevated temperature when placed in the wall thereby avoiding thermal shock, and heating the furnace to a higher temperature sufficient to burn away said straps and fuse the brickwork of said arch unit.

LOWELL M. KIRK.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 762,417 Johnson June 14, 1904 1,132,028 ODonnell Mar. 16, 1915 1,355,115 Cook et'al. Oct. 5, 1920 1,530,628 Troutman Mar. 24, 1925 1,677,002 Olson July 10, 1928 1,824,222 McLimans Sept. 22, 1931 2,377,279 Stewart May 29, 1945 2,408,387 Gay et a1. Oct. 1, 1946 

